Electrical connection



Filed May 16. 1931 w H m wiw 8 awpw 0 5 n 1; Z n 1 a n k 2 0 MW z J a m j M Z 7. (U J F 1 8 K, a; z 7 Z I p m 0 7. 0 L F 2 J :9 H 2 5 1 w a .2 w 4 1 AI 3 patented Sept. 18, 1934 umrso srA'rEs FATE ELECTRICAL CONNECTION Massachusetts Application May 16, 1931, Serial No. 537,888

8 Claims.

This invention relates to an electrical connection in which a fuse is employed to complete the circuit in which the electrical connection is included.

The invention is particularly applicable to an electrical connection of that character in which a plug member c0-operates with a socket member, and is herein shown as embodied in the plug member of said connection.

The invention has for its object to provide a plug or socket member which may be economically manufactured, is simple, durable in construction and efficient in operation, and to this end said plug or socket member comprises terminal members spaced apart and one of which is provided with a contact member extended outwardly therefrom, a fuse unit interposed between and mechanically and electrically connecting said terminal members together to form a terminal unit, and a tubular member open at its opposite ends and into which said terminal unit is inserted and removed therefrom through one end thereof. Provision is also made for insulating the improved electrical connection, and also for relieving the connections of the fuse unit with the terminals from strain when the plug member is pushed into or withdrawn from the socket member.

These and other features of this invention will be hereinafter described and pointed out in the claims at the end of this specification.

In the drawing illustrating the preferred embodiment of the invention Fig. 1 is a side elevation of one form of plug member embodying this invention;

Fig. 2, an end elevation of the left-hand end of the plug shown in Fig. 1;

Fig. 3, a vertical longitudinal section: of the plug shown in Fig. 1;

Fig. 4, a longitudinal sectional view illustrating parts of the plug assembled ready to be inserted into the outer metallic shell shown in Fig. 3;

Fig. 5, a plan view of the terminal unit construction used in the construction of the present plug member;

Fig. 6, an end View of one of the terminal members shown in Fig. 5, looking in the direction of the arrow thereon, and

Fig. 7, a longitudinal section of a modified form of plug member embodying the invention.

In general the invention contemplates a novel construction of electrical plug member provided with an outer shell having therein a cable terminal to which the end of the cable may be attached, and a plug terminal or contact member for co-operating with the usual socket member with which the plug member is designed to be used. The cable terminal and plug terminal are located within the outer shell and each provided with means for detachably holding the end portions of a fuse cartridge. Provision is made for spacing the cable and the plug terminals within the outer shell in predetermined relation to each other and to the ends of the outer shell, and also for taking the thrust from the fuse when the plug terminal is plugged into the usual socket member.

Referring now to the drawing which as above stated illustrates the preferred embodiments of the invention, the plug member illustrated in Figs. 1 to 6 inclusive comprises an outer metallic shell 10 herein shown as formed of an openended metal tube, one end of which is provided with an inwardly extended curved flange 11 as illustrated in Figs. 2 and 3, and the second end of which is threaded and has removably secured thereto a cap member 12 provided with a cableguide 13 held in swivel connection thereto and through which the end of the cable may be inserted for connection to the cable terminal 14 as will be described. The plug member is provided with the cable terminal 14 and also with a plug terminal 15, and in the preferred embodiment of the invention the cable terminal 14 and plug terminal 15 have provision for detachably holding and making contact with the ends of a fuse cartridge 16 in a manner such as to enable the cartridge 16 to act as a rigid connector between the plug and the cable terminals as well as completing the circuit through the fuse, so that the three parts may form a terminal unit and may be inserted and removed as a unit from within the outer metallic shell 10 of the plug through one end thereof as will be described.

As herein shown the cable terminal 14 com prises a metal disk 17 having a socket member 13 provided with a socket 19 into which the end of the cable may be inserted and soldered to connect the cable to the socket member 18. The disk 17 is provided with an angle-shaped bracket 190 riveted or otherwise secured thereto and which is preferably provided upon its projecting flange with a spring clip 20 secured thereto by a screw 22 or otherwise, to permit the end of a standard fuse cartridge 16 to be inserted down between the spring arms of the clip 20 so as to frictionally and detachablyhold the end of the cartridge and to both mechanically and electrically connect the fuse cartridge to the cable terminal.

The plug terminal 15 is herein shown as provided with the usual form of plug contact member extended from a metallic disk 26, which is provided with an angle bracket 27 secured thereto. A spring clip 28 for the reception of the second end of the fuse cartridge 16 is secured to the projecting flange of the bracket 27. The fuse cartridge 16 as above stated may and preferably will be of a standard construction comprising in general an insulated cartridge having a "fuse therein and provided with metallic terminal rings 30 at each end, designed to be inserted into the standard spring clips 20, 28 as illustrated.

In order to insulate the metallic disks 17, 26

the cable terminal, the plug terminal, and the cartridge 16 may and preferably will be assembled within an insulating tube 32 of a size-such as to fit snugly within the outer metallic shell 1 0. 1

Provision is made for spacing the cable and plug terminals at predetermined. distances from each other and from the ends of the outer shell 10, and as herein shown three insulating tubes 38, 39, are provided.

The end spacing tubes 38, 40 are adapted to engage with the outer surfaces of the metal disks 1?, 26 of the cable and plug terminals, while the inner spacing tube 39 is interposed between the inner surfaces of such disks, as illustrated in Figs. 3 and 4. a

In the construction and assembly of the illustrated plug, the end of the cable is first passed through the cap member 12 before the latter is screwed onto the metallic outer shell 10, and the end of the cable is soldered within the socket 19 of the cable terminal 14.

Thereafter the terminal and fuse unit comprising the cable terminal 14, the plug terminal 15, and the interposed fuse cartridge 16, is pushed into the interior of the insulating tube 32, and during this operation the spacing tubes'38, 39, 40, are introduced into their proper positions with the ends of the tubes engaging the opposite faces of the disks of the cable and plug terminals as above set forth, the tube 39being in two pieces or halves as indicated by the line 41 in Fig. 4.

The outer spacing member 40 at the plug end projects slightly beyond the end of the insulating tube 32 so that when the unit shown in Fig. 4 is introduced through the threaded and open end of the metallic shell 10, the end of the spacing tube 40 co-operates with the turned-over lip 11 0f the outer shell 10, to enable the spacing tubes to function as thrust members, when the plug 25 is plugged into the socket in the use ofthe device. I

Thereafter the cap'member 12 which has as above stated been strung upon the cable, is screwed into operative position upon the threaded end of the outer shell and the assembly of the plug is complete. v

In the use of the plug member, the thrust of the plug contact member 25 of the plug terminal member 15 is taken by the spacing members 38, 39, 4c and transmitted to the outer shell 10 independently of the fuse cartridge, thereby avoiding any tendency toward the dislocation'of the fuse from its terminal members during the use of the plug.

From the description thus far, it will be apparent that the terminal fuse unit comprising the plug terminal, the cable terminaLand the fuse cartridge operatively but detachably connected with the plug and cable terminals; contributes to the ease with which the present plug may be assembled, and also facilitates the renewal of the fuse when the latter has become blown out.

The construction is simple and may be economically manufactured, and the provision of the spacing tubes 38, 39, 40 prevents the displacement of the fuse cartridge from its operative engagement with the spring clips of the plug and cable terminals.

- -The disks 17, 26 serve to properly center the plug and cable terminals within the insulating tube'32a'nd the outer tubular shell 10, and thereby properly position the contact member 25 of the plug terminal with relation to the contact jmember of the co-operating socket member, not

shown.

It will be observed that the insulating members 32; 39 and'th'e spacing members 38, 40 may be made by cutting standard tubes of insulating material of the proper diameter into the required .or desired lengths, which tends. to reduce the cost of the device. 1 I

The electrical connection above described and illustrated in Figs. 1, 3 and 4, and in which an outer metallic shell 10 is employed may be used in circuits carrying low andrelatively high tension currents, but in some cases where extremely high tension currents are used, the-metallic shell 10 may be omitted and a tubular member of in.- sulating material of increased thickness maybe used asillustrated in Fig. '7, wherein a tubular member 50 of insulating materialis shown as of greater. thickness than the tube 32 in Figs. 3 and l, and wherein the outer end is shown as of greaterthickness than the body portion so as to provide the shoulder 51 for the spacing disk 26'to' bear against. 7

In the construction shown in Fig. '7, the body portion of the tubular member 50 is substantially equal to the thickness of the tube 32 and metal I shell 10 shown in Figs. 3 and 4, and the front end vof the insulating tube 50 is of a thickness equal to the shell 10, tube 32 and member 40 of the construction shown in Figs. 3 and i.

In the. plugmember shown in Fig. 7, itwill be observed that the terminal unit is insertible into and removed from the tubular member 50 through one end of the latter.

.The.invention isherein shown as embodied in the plug member of .a plug and socketv connection, but it'is equally adapted to be embodied in the socket member if desired, and by the term plug member as employed in the claims, it is desired to include the socket member of the plug and socket connection; r

. While preferred embodiments of the. invention have been herein illustrated and described, it will be understood that the invention may be embodiedin other forms within the scope of the following claims. I

Having thus described the invention, what is claimed is: V l

1;. An'electrical plug for use in'connecting a plug to a socket comprising a plug terminal provided with a centering disk, a cable terminal provided with a centering disk, a fuse member interposed between and co-operating with said terminals to form a portable unit, an outer protective shell, and a' plurality of tubular spacing members located within said outer shell and cooperating with the centering disks of said terminals to space the same.

2. An electricalplug for use in connecting a plug to a socket comprising a plugterminal, a

co-operating with said terminals to form a portable unit, an outer metallic protective shell of greater length than said terminal unit and within which the unit is operatively positioned and provided with a lip at one end thereof, and with a removable cap at the other end thereof, and spacing members interposed between the plug and cable terminals and said lip and the cap respectively, and an intermediate spacing member interposed between and co-operating with said plug and cable terminals.

3. An electrical plug having, in combination, a terminal unit comprising a plug terminal, a cable terminal, and a fuse forming a connection between said terminals, an outer protective shell projecting beyond each end of said terminal unit and provided with an open end adjacent the plug terminal, and provided upon its second end with a removable cap through which the cable may be passed when removed from the protective shell for connection to the cable terminal.

4. An electrical plug having, in combination, a terminal unit comprising a plug terminal, a cable terminal, and a fuse forming a connection between said terminals, an outer protective shell projecting beyond each end of said terminal unit and provided with an open end adjacent the plug terminal, and provided upon its second end with a removable cap through which the cable may be passed when removed from the protective shell for connection to the cable terminal, and insulating and spacing tubular members co-operating with said terminals and with said outer shell.

5. In an electrical connection, a plug member comprising an outer metal tube open at its opposite ends, an inner tube of insulating material fitted into said outer tube, a terminal unit insertible into and removable from said outer tube through one end thereof and comprising terminal members and a fuse unit mechanically and electrically connecting said terminal members and insulated from said metal tube by said inner tube.

6. In an electrical connection, a plug member comprising an outer metal tube open at its opposite ends, an inner tube of insulating material fitted into said tube, a terminal unit insertible into and removable from said outer tube through one end thereof and comprising terminal members and a fuse unit mechanically and electrically connecting said terminal members and insulated from said metal tube by said inner tube, and thrust and spacing members surrounding said terminal unit within said insulating inner tube.

7. A terminal unit construction comprising terminals spaced apart and provided with metallic centering disks and with spring clips, an interposed fuse unit engaged with said spring clips to mechanically and electrically connect said terminals together so as to be moved as one piece, and a tubular member of insulating material into which said terminal unit is inserted as one piece and with which said metallic disks co-operate to center the terminal unit therein.

8. A terminal unit construction comprising terminals spaced apart and provided with metallic centering disks and with spring clips, an interposed fuse unit engaged with said spring clips to mechanically and electrically connect said terminals together, a tubular member of insulating material into which said terminal unit is inserted and with which said metallic disks co-operate to center the terminal unit therein, tubular thrust members co-operating with said disks and with said tubular member for taking the thrust from the fuse when the plug is used.

CHARLES H. REYNOLDS. 

